A New Mix Composition to Increase the Shelf Life of Emulsion Based Bitumen

8/13/2019 A New Mix Composition to Increase the Shelf Life of Emulsion Based Bitumen

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A New Mix Composition toIncrease the Storage Life ofIndonesian Bitumen EmulsionM Hermadi and A B Sterling


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222NEW MIX COMPOSITION TO INCREASE THE STORAGE LIFEOF INDONESIAN BITUMEN EMULSION

Madi HermadiInstituteof Road Engineering Research and Development AgencyMinistry of Public Work IndonesiaDr A B SterlingTransport Research Laboratory

Road Research Development Project IRE IndonesiaMadi Hermnadi is a researcher, born on August 9, 1964. Graduated from Department ofChemistry, Institute for Islamic Studies, Bandung, Indonesia, 1992. Involved on road materialsresearch at IRE since 1985.Dr Sterling graduated in 1963 and ga ined his Ph.D. inhighway engineering in 1975. He is anindependent consultant and has been working as a Pavement Engineering Specialist at IRE asa member of the UK Transport Research Laboratory team since 1995.

1 INTRODUCTIONBitumnen emulsion is often used for pavement mixes in Indonesia, especially in locationswhere there is a shortage of hot-mix plants. Current formulations of emulsions have astorage life of about three months. In Indonesia the typical site storage time is frequentlymore than three months, nine months being quite common. This situation arises becausesupplies to outlying areas fend to be made only at quite long intervals. The fact thatemulsions are stored for longer than three months leads to poor quality asphalt or total lossof the emulsion.IRE research in 1995 (Tjitjik, 1995) about the ways of handling bitumen emulsion showedthat bitumen emulsions made in Indonesia, especially CSS type, had storage lives of onlyIwo months when retained in a drum without turning. When the drums were turned once amonth, the storage life increased to, typically, five to six months.This paper describes an IRE research project designed to find formulations for bitumenemulsion that will significantly increase storage life.

2 LITERATURE2.1 Bitumen EmulsionBitumen emulsion is a mixture of two phases, that is an aqueous emulsifier solution ascontinuous phase and tiny droplets of bitumen as the discontinuous phase. The bitumenparticles are typically in the size of 0.1 to 5 micron and are usually stabilized by an ionicemulsifier2.2 EmulsifierBased on the charge, there are three types of emutsifier. Those are cationic, anionic, andnon-ionic emulsifiers. Indonesia currently uses cationic emulsifiers.2.3 The Ways of Increasing Storage Stability of Bitumen EmulsionAccording to Stoke's law, the rate of settlement is determined by the following formula:

v = 219 x gr' (dl-d2)I,

where, v = the rate of settlementg = gravityr= radius of bitumen particles

cl1= specific gravity of bitumencd2 =specific gravity of liquid phasep= viscosity of liquid phase

Considering the formula, we can see the rate of settlem~ent depends upon:. Viscosity of the continuous phase.* Difference in specific gravity between the two phases, and* The size of bitumen particles.It follows that there are changes in the formulation of bitumen emulsions that may beexpected to improve storage stability. They are as foltows:

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'a5a5E5E-aa aaaaaa) The higher the specific gravity of bitumen the faster the bitumen phase will settle. Addingkerosine to the biturnen, before emulsifying, will decrease the specific gravity of bituiiienphase which should reduce the rate of settlement. Likewise, increasing the specificgravity of the aqueous phase should also reduce the rate of settlement.b) Storage stability of bitumlen emulsion should be increased by increasing the viscosity ofthe aqueous continuous phase.c) Reduction of particle sizes of the bitumen phase should increase storage stability.Additional factors that should/may alter storage stability are.a) Type and quantity of emulsifying agent.b) Bitumen content andlor viscosity of the emulsion.3 EXPERIMENT IN LABORATORYThe research investigated both cationic medium setting (CMS) anid cationic slow selling(CSS) emulsions t find the optimum compositions by varying:.* Colloid Mill condition i.e. particle size distribution of bitumen droplets,. enmulsifiei type.* kerosene content of bitumien,* bitumien content of the emulsion,. emulsifier content of the aqueous phase, and. CaCI2 content of the aqueous phase.

3.2 Emulsifier TypeFigure 1. Effect of Emulsifier Type on Settlement

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There are only five emulsifiers currently available in Indonesia. Three of these are for CMS,namely Asfier-103, Asfier-123, Asfier-208. Two are for CSS, namely Polyram-SL andRedicote. The research examined the changes in settlement rate caused by use of each ofthe above. The results are shown in Figure 1 above.3.1 Colloid Mill ConditionIn this investigation, bitumen emulsions in many compositions were produced using alaboratory colloid mill. The gap size and the rotor speed of the laboratory colloid mill cannotbe changed. Theretore, the laboratory colloid mill cannot be adjusted to achieve the sameparticle size distribution as the factory colloid mill. Storage stability of bitumen emulsionsproduced by the laboratory colloid mill are lower than those produced by the factory colloidmill. Therefore, the first step of this investigation was calibration to determine the correlationbetween the storage stabilities of emulsions from the two sources.Seven bitunmen enmulsions were produced by each of the following processes: the factory colloid milfl,* the laboratory colloid mill using a single pass and* the laboratory colloid mill with double passes.The bitumen emulsions were compared in settlement value anid thle results are shown inFigure 1below.Settlement value is the difference in residual bitumen content, percent, between samplestaken fron, the lop and bottomn of a 500 ml cylinder after storing for one or five days.Figure 1 shows that bitumen emulsion produced by a single pass through the laboratorycolloid mill had higher settlement values than those produced by the factory. Those usinrg adouble pass through the laboratory colloid mill had very similar settlement values toemulsions produced by the factory.Hence double passes through the laboratory mill were used for the rest of the experiments.

As shown in Figure 1, the emulsifiers that produced bitumen emulsions with the lowestsettlements were Asfier-103 for CMS and Redicote for CSS. These emulsifiers were used forthe remainder of the experiment s.3.3 Variation of Penetration Grade BitumenThe penetration value of the bitumen feedstock influences the storage stability of theemulsion, possibly via changes in he bitumen specific gravity (SG) and/or through the effectof bitumen hardness on particle size distribution. The influence of bitumen penetration on thesettlement of emulsion is shown on Figure 2.

Figure 2. The Influence of Penetration on Settlement of Emulsion0006

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224.Figure 3. The Effect of Adding Kerosine on Penetration

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300 _____250 -__ i___200. ____ __ _1s0 ;7- ~7- __ __50,0 +-, '--I,

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0 169 3 45 '435 5 26 6.19 714 8 11 f Kerosine

Bitumens produced in Indonesia by Pertamina are AC pen 60/70 and AC pen 80/100, Theliterature indicates that pen 180/200 is a more common bitumen grade for use in productionof emulsion. In order to produce a bitumen of 180/200 grade, 60/70 was blended withkerosene. The effect on the penetration grade, of adding kerosene to 60/70 bitumen isshown in Figure 3.As may be seen in Figuire 3, above, 4.3 kerosene must be added to the bitumen toincrease the penetration value to 200. This also has the effect of reducing the bitumen SG.3.4 Variation of Bitumen ContentIncreasing the bitumnen content of a bitumen emulsion increases both emulsion viscosity andstorage stability. The influence ot bitumen content on storage stability and viscosity ofbitumen emulsion is shown in Figures 4 and 5.

35030025020015010050

Figure 5. The Influence of Bitumen Contenton Settlement of Emulsion

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*CMS-2, C

60 63 65 68 70 75 80Biiurnen Conteni l

Figure 5, above, shows that a higher bitumen content leads to increased storage stability ofbitumen emutsion. Bitumen contents used in current production are designed to achieveemulsion viscosities complying with the relevant specifications. The specified viscosity rangefor CSS-1, at a temperature of 25'C, is 20 to 100 seconds. For CMS-2 it is 50 to 450seconds at a temperature of 500 C. Considering Figure 6. the ideal viscosity of CSS-1 is 60seconds which can be reached at bitumen content of 70 to 72 . The minimal residuecontent of CMVS-2 is 65 0/, so bitumen containing about 10 0/ of kerosene would leave 650/residue if 72 0/ of cutback bitumen emulsion were used in the emulsion.3.5 Variation of.Emulsifier Content

Figure 4. The Influence of Bitumen Contenton Settlemet of Emulsion

4~~~~~~~- ; c ssiii( day)__________________________i days

&Ms.2__ __ __ _ __i day)

60 63 65 68 70 75 80Bitune,, Conlicni ( i

The amount of emutsifier used in bitumen emulsion depends on the bitumen content of theemulsion. There is an optimal content of emulsifier to achieve the highest value of storagestability. If the content of emulsifier is too low, the bitumen droplets will soon precipitate. Ifthe content of einulsifier is too high it can cause the emulsion to bubble and excessive aircontent can destroy the emulsion. The influence of emulsifier content to storage stability ofbitumen emulsion is shown in Figures 6 and 7.Figure 6 shows that the optimum content of emulsifier Asfer-103 is 0.4 or CMS-2 bitumenemulsion, Figure 7 shows that the optimal content of Redicote emulsifier is 0.48 or CSS-1biturnen emulsion. At those emulsifier contents, the emulsion had the lowest value ofsettlenient.

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5 aa au a aau yWa-aFigure 6. The Influence of Emulsifier Contenton Settlement of Emulsion CMS-2 Type Figure 8. The Influence of CaCI 2 Contentto Sattlement of Emulsion5

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0.1 0,2 0.3 0.4 0.5 0.6 0.7 0.1Ernuis~ifi,Coiiont 1%)

Figure 7. The Influence of Emulsifier Contenton Settlement of Emulsion CSS-1 Type

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*1 day

*5 days

0 0.1 0.2 0.3 0.4 0.5 0.6 0.1 0.8E nuls~ifieronient

3.6 Variation of CaCI 2Sometimes cationic emulsifiers combine with unexpected anions and are precipitated assediment. Calcium Chloride, in cationic bitumen emutsion, acts as a stabilizer that inhibitssuch sedimentation. CaCI2 also increases the density of emulsifier solution and henceincreases the storage stability of the emulsion. The influence Of Ca1C12 on storage stability ofbitumen enmulsion is shown in Figure 8.Figure 8, below, indicates that the optimnal content of CaCI 2 is 0.3 .This condition gives thebest storage stability of CMS-2 bitumen emutsion. The optimal content of CaCI 2 could bedifferent if the quality of water in the emulsion changed.

cad?2 Content ( 1

* cM5.3I day5 days

A css-i25 I day

5 days

3.7 Optimal Composition of Bitumen EmulsionUsing the results of the experiments described above, the optimal composition of bitumenemulsion was determined and is presented in Tables 1and 2.

Table 1. Composition of Bitumen Emulsion CMS-2 TypeElement of emulsion CompositionCMS-2 Type Modified ConventionalBitumen, 65.00 63.00Kerosine, 7.00 7 00Emulsifier, 0.40 0 30Hl-c, ____0.40 0.30CaCI,. 0 30 0.10Water. 27 90 29.30

Table 2. Composition of Bitumen Emulsion CSS-1 TypeElement of emulsion CompositionCMS-2 Type Modified ConventionalBitumen. 65.20 59 00Kerosine. 2.80 1.00Emulsifier, 0.48 0.40Hcl, _____ _0.48 0.40Cad.. . ________ ~ 30 0 10Watec - ~~~~~~304 39.10

3.8 The Monitoring Quality Result of Modified Bitumen EmulsionMonitoring the quality of modified bitumen emulsion CMS-2 and CSS-1 shows that it can beplaced iii 9 iioviths aud will still comply with the specification.

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p _ _ _ _ _ _ _ _ _ _ 0.05 0.1 0.15 0.2 0.25 0.3 0

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226Table 3. Quality of Bitumen Emulsion CMS-2 Type

Characteristic specification CMS.2 Modified CMS.2 ConverrtionalMn Max 0M M G 9 m 0 m ~ M ~Viscosiry. SF at 50Gl S 5 450 257.6 25 7.3 2.57.8 257.7 252.6 252.3 253 252.8SettlernenI lesi, 1daIL/ 0.36 04A7 0. -07-8 (142 0.4-5 0.63 oGyitSetllement lest. 5 (lays. 5 3.18 1,55 3.8. 4.22 3.45 34 2 47Coaling abilly and whly;resistance*Coaling dryaggregate good good good good good good gooui good 9(10(*Coaling ahflespraying good good good good good good good good good*Coaling wet aggregate good good good good good good good good tood*Coaling alber s Pray~ring,,,,,, od good good good good good good ,,29 d0l1 goodParticle cliarge lest Positive * 0 .Sieve lesl 0.1 0 0 0 0 0 0 0 0Waler content., 28.20 2 7.21 27.45 27.33 26.48 27.27 20.51 26.13Oil distillate. 0/% 12 6.1 6,5 6.3 6.2 6,2 6.3 6.3 6.Residue. 65 66,8 66.8 66.2 66,5 65.5 65.3 65.6 05.4Testn residue* enetratron.5 C. 100g9. 100 250 214 215 215 215 215 214 214 2150. imm-Ductility,25C. cm 40 '140 '140 v140 .140 '140 >140 '140 140* olubilityn 97.5 gg 99 99 99 gg 99 99 99 iclrctoroelhylene./Speciticravity .0.958 0.958 0,958 0.958 0.958 1 0.9580.5 8

Note: M =Months Age 01 itumen emuliron)

Table 3, above, shows that the quatity of modified CMS-2 bitumen still meets thespecification after 9 months. Table 4. below, shows that the quality of modified CSSi-1bitumen emulsion still meets the specification after 9 months. Whereas the quality ofconventional CSS-1 will not meet the specification in 3 months, and it wilt precipitate in 6months.

Table 4. Quality of Bitumen Emulsion C5SS-Type

NOW m = monrths Age or

Characteristic ISpesitication CSS-1 Modification css-1 ConvenioiratMim Mao Om 3 M m 9M Om 3MViscosity,F t 25'C. s 2-0 100 48.6 48.6 48.5 48.6 20,2 19.5Sarrierrieniest, ay,0/% 1 0.13 0.16 0.17 0.85 0.75 2.60Salitemnentest. ays. 5 1.03 1,23 1.82 4,23 4.30 5.23Pardicle charge test Positif vB v v 0 il~itrirenSieve est.t 0.1 0 o 0 0 0 0 EmnulsionCeenrrtixinigest./ 2 1,30 1,32 1,33 1,76 1.80 1.83 sWater conrentl./. 31.62 31.82 31.62 31.62 39.22 39.25 SettledOit dostriate. Ot% 3.31 3.05 3.45 3.34 0.50 0 71Resida. 0/5% 54 67.74 65.46 04.62 59.81 C597lest on resrdu-Penetration. 25C, 100 100 250 135 135 134 135 122 123Ouc1)itlYity . IM 40 140 140 140 140 140 > I40oSolubilityn 9 75 99 99 99 .99 99 99Trichlofoe~irytene, 0/ ______Specificravity 6.96 09-62 0.62 0,962 0.1 60o .9 i)_____

4. USING MODIFIED EMULSION IN FIELD EXPERIMENTA field experiment was performed in which Slurry Seal was mixed and laid to compare the

use of modified and conventional CSS-1 emulsions as a binder. The experiments usedemulisons, both modifted and new, that had been stored for 3, 7 and 9 months. A controlsectton was also latd using new, conventional CSS-1 emulsion.4.1 Specification of Slurry Seal MixtureHere are fottr specification of four types of Slurry Seal mixture.

Table 5. Specification of Four Types of Slurry Seal MixtureCharacteristic of _________SpecificationSlurry Seal Mixture Type I Type 11 Type 111 Type IV

Gradation of aggregate,passing:Sieve size :112 100318 *100 100 85-100No. 4 100 90 -100 70- 90 60-85No. 8 90. 100 65-90 45-70 40.60No, 16 65-90 45-70 30-50 28-45No. 30 40 60 30-50 18-34 19.34No. 50 25 -42 18 30 10 -25 12 -25No. 100 15 -30 10 21 7 18 7 18No 200 10 20 5 -15 5 i 4

Residual bitumen content. 10.0 -16 0 7.5 13.5 6,1 11.0 5.5 -8,0weight of ry ggre ateApptication rate . kg/rng 3.5 5,0 5.5 -8.0 8,0 18.0 10.0 -15.0based on mass ot dryaggegtCondition of Slurry Seatl Semi fluid -Semi fluid -Semi fluid -Semi luiMixture -Smooth -Smooth -Smooth -Smooth

Homogenous Homogenous Homogenous Iomogenous-No emutsion -No emulsion -No emutsion -No emulsionrun off run off run off run ott

4.2 The Quality of Material for Field Experiment of Slurry SealThe quality of bitumen emulsion and aggregate used in this field experiment is shown inTables 6 and 7.

Table 6. The Quality of Bitumen EmulsionNo Ournern EnruisionCirar`actecistic of L

2

4-6

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Viscosiry. SF at 25`C_bi.ttIL.ntioi it e5r.1(try_Setttliemert test, 5 (laiysSieve rest.cSi ierot ri v g %itOit disoiiiiate. /Rtesiduie I

Specitication uuiatit of fihiunren Lnmutsionbb.1Modified Conven. UnitsMin Max ~3 7 M 9M tiorral20 10 68.5 69.2 67.3 20.5 secondsLi 0,15 0.34 0.68 0.65

5 1.25 2.31 4.0 7 3,77Positive v

). 0 0 0 0 _2 1.50 1.70 1,80 1.s0 /29 7 27 6 28.3 38.4 oto

13.25 1 3,32 1 3.12 0.5057 64.2 64,8 63.7 58.6

I w. W WuuW wW vuW W WW w u W W

Particle chaige testoitumen emulsion)

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p pp pp aa a' M 5 a55 a uvISpecrtication

Table 6. The Quality of Bitumen Emulsion (continued)utlatil 01 iittsnrrer~ni-riil ClSS1Liiaracteirstic otNo. Btium~en Emnulison ____Modified Conivelr UnitsMin Max 3 M 7M 9 M timonil

10. Test on residue:Penetration, 25'C. 100g., 100 250 134 134 135 123 0.1 nim0.1 FrimlrD uctility .25'C, cni 40 > 40 >140 '140 > 140 crrr

*Solubility in 97,5 99 99 99 99Tticlriotoeithyleene11 Specific Giavity ____ _____ 0,9585 -0,9588 0.9587 0.9007

Table 7. The Quality of Fine Aggregate ex CilacapSpecilication Result of lest Units

No. Characteristic of Aggregate Min MaxGradation ot aggregate.passing__ ___Sieve size 3/8 *.100No, 4 __ _ _ _ _ _ _97.5

No 8 _ _ _ _ _ _ _ _ 82,9No. 16 *-58.6 __ _ __ _No 30 -39.5No 50 _ _ _ _ _ _ _ _ 29.7No 100 _____ 16,3 0/No 200 *.7,3 __ _ __ _

2 Spr152ic G ravity _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ lik 2,500 __ _ _ _ _ 2.630 _ _ _ _ _

*SSO 2,500 _ _ _ _ 2.690 __ _ __ _3

.AirpaterriAbsr,,bti,O,I enfsii

2.500O 2.790

0.25 -3

0,15'3

4.3 Design of Slurry Seal for Field ExperimentThe gradation of aggregate, ex Cilacap, is shown in Table 7 above, and meets thespecification of Slurry Seal Type II.4.4 Bitumen emulsion CSS-1 ContentThe content of bitumen emulsion CSS-1 type is staled base on the following formula.

P = 0.05A+0.1B+0 5Cwhtere,P = Percentage of bitumen emulsionA = Percentage of aggregate that contain in No.8 sieve (17.1 0/)B = Percentage of aggregate passing No.8 sieve and retained on No.200 (75.6 )C = Percentage of aggregate that pass in No.200 sieve (7.3 /)

For modified CSS-1 bitumen emulsion content, multiply the calculated content of bitumenemulsion from the formula by the correction factor of residue content 58.16-64.2. The value of58.6 is the residue' of conventional bitumen emulsion and 64.2 is the residue ofmodified bitumen emulsion.Hence:Modified CSS-1 bitumen emulsion contentConventional CSS-1 bitumen emulsion content = 10.35= 12.07 /

4.5 The Content of Cement in Slurry Seal MixturePortland cement, chalk, and fly ash may all be used as mineral fillers in order to meet thespecified aggregate gradation or to modify the time-to-break of the bitumen emulsion. Weuse Portland cement in this trial in order to achieve the break time of 30 minutes, the timeneeded in field experiment from mixing to pouring the mixture using locally producedequipment. The result of adding cement filler to Slurry Seal is described in Tables 8 and 9.

Table 8. Bitumen Emulsion CSS-1 ModificationPercent of Cement Breaking Time0 60 minutes0,5 45 minutes1 30 minutes Optimum1,5 20 minutes2 15 minutes

Table 9. Bitumen Emulsion CSS-1 ConventionalPercent of Cement Breaking Time0 60 minutes0,5 45 minutes1 30 minutes Optimum1,5 20 minutes2 15 minutes

4.6 Optimising Added WaterAdding water in Slurry Seal is to get mixture with characteristics semni fluid, smooth,homogenous and without emulsion run off. The result of adding water to Slurry Seal isdescribed inTables 10 and 11.

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228Table 10. Adding Water for Slurry Seal CSS-11 Modification

Adding Water Semi fluid Smoothly Homogenous Norun off15 No No No No20 No No Yes No24 Yes No Yes No26 Yes ___No____ Yes NO28 Yes No Yes No3O0 Yes Yes Yes N-1o32 Yes Yes Yes Yes__34 Yes Yes Yes YesOptimumTable 11. Adding Water for Slurry Seal CSS-1 Conventional

Adding Water Semi fluid Smoothly Homogenous No______________________ ~~runff10 No No No No14 No No Yes No16 Yes No Yes No18 Yes NO Yes No19 Yes NO Yes No20) ~~Yes Yes Yes N21 ~~Yes Yes Yes N22~YesYsYe-e

Note : ) = ptimum

Figure 10. Simple Equipment for Slurry Seal

Table 13. Pavement Condition and Traffic Before and After Application of Slurry SealNo Survace CSS-1 Modirication CSS-1 Modification CSS.1 Modification3 Months Age 7MonthsAg 9onhAgCondition Before After Before After Aplication Before AfterApticat on -Aptication Apticafion ___Apircation Aplication

___________ ________ Mod Con. Mod. 1 Con. Mod. ConAvextage. cmeth t.8.6 0 .7 Q ,A.veraredeph 00c0m06 08 08 0 6 0

2. Skid Resistance 47.5 -62.5 64.7 48.3 -63 7 52 9 -63 4 65 33. Survace 453 good good 52.2 barik 65.3 good goodCondition Ra-lngRavelin ___ Ravering-4 Tiafic per day 52 51 21 5186 5186 5605 5605 15605Note Mod = Modification Con. = Convent ional4.7 The Result of Field Experiment of Slurry Seal MixtureThe trial of Slurry Seal was laid in Jatan Jenderal Sudirman KM I-Cilacap on February 5.1997, in Jatan Gatot Subroto KM 5 Cilacap on May 5 1997 and in Jalan Sutomo KM. 7Pekalongan. The Slurry Seal was mixed and laid using simple equipment that can easily bebuilt in any part of Indonesia. The equipment is illustrated in Figure 10.4.8 Pavement Condition and Traffic Before and After the ExperimentThe condition of Slurry Seat and traffic when the experiment was done is given in Tables 12and 13.

Table 12. Visual Condition of Slurry Seat Mixture

5. CONCLUSIONSa) Because of the remoteness of some of its parts. Indonesia needs bitumen emulsion withhigh storage stability, that can be stored about 6 to 9 months.b) The storage stability of Indonesian bitumen emulsions, CMS and CSS, can be increasedby changing their composition.c) The optimum composition for CMS-2 bitumen emulsion is 65 bitumen. 70/ kerosine,0.40 emulsifier (Asfier-103), 0.40 H Cl. 0.30e/ CaCI2 and 27.90 / water.d) The optimum composition for CSS-1 bitumen emulsion is 65,20 / bitumen. 2.80

kerosine, 0.48 emulsifier (Redicote), 0.48 H Cl. 0.30 CaCI2 and 30.74 /water.e) The study has shown that bitumen emulsions CMS-2 and CSS-1, with optimumcomposition, can be stored for up to 9 months.f) A field experiment demonstrated that changing the composition of bituinen emulsionCSS-1 to that described above does not effect the characteristics of Slurry Sealproduced with this material.g) Slurry Seal, made with the new emulsion, was placed successfully after storing theemulsion for 9 months. A simple mix-and-spread machine was used that is designed forlocal production.

Note

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A New Mix Composition to Increase the Shelf Life of Emulsion Based Bitumen